Tool for cleaning commutators and the like



July 31, 1934. N4; F.'l-y/|NAUGHT r-:r AL 1,958,215

TOOL FOR CLEANING COMMUATOR AND THE LIKE Filed Jan. 8, 1934 PatentedJuly 31, 1934 TOOL FOR CLEANING COMlVIUTATOR/S AND THE LIKE Norris F.McNaught and Edward H. Peterson, Chicago, Ill., assignors to Duro MetalProducts Company, Chicago, Ill., a corporation of Illinois ApplicationJanuary s, 1934, serial No. 705,686

6 Claims.

Our invention contemplates and provides a handy tool which yispeculiarly suitable for cleaning and/or removing rough spots from theVcommutators of dynamo-electric machines, but which is neverthelesscapable of and intended for use in cleaning and smoothing contactrings,` distributor points, breaker contacts, fe'tcl The tool of ourinvention, as illustrated in the accompanying drawng, comprises anelongated pointer or cleaner arm, preferably constituted by a metalstrap which isconformed at one end portion to provide a handle-eye forreceiving, carrying andy dispensinga supply of abrasive strip to lbeVextended along theupper and lower surfaces of the pointer and around thetip thereof; that end portion of the metal strap whichis conformed toprovide the handle eye also being conformed V`to provide a clamping armwhich overlies the adjacent portion ofthe pointer and cooperates with anappropriate shackle to clamp a tautene'd abrasive strip to the upper,and lower surfacesof that portion of the pointer whichis embraced by theshackle. ,i

. The invention-has for its objects to provide a tool of the classmentioned which is of simple construction, comprises a minimum of parts,and which is economical to manufacture and easy to manipulate. v Y n y'Other features, objects and advantagesof-our invention will appear fromthe followingdetailed descriptionv wherein reference is made to theaccompanying drawing, in which Fig. l is aitopplan View of a preferred`emu bodiment of our invention;

Fig. 2 is aside elevational view of the tool illustrating how it maybemanipulated toi-effect the cleaning of the segments of avcommutator;

Fig. '3 is' a fragmentary sectional view taken on the line 3 3 of Fig. 1and looking in the direction indicated by the arrows;

Fig. 4 is a view generally similar to'Fig.l 3,`but illustrating theparts of the tool in the relative positions which they assume when theclamping shackle is moved to its non-wedging position;

Fig. 5 is a view generally similar to Figs. 3 and 4 illustrating how theclamping shackle may be Withdrawn .from its embrace of the pointer vandclamping arm of the tool when there isv no abrasive strip on thepointer; I

Fig. 6 is a perspective illustrating the abrasive roll andclampingshackle disassociated from the other parts of the tool; and

Fig. '7 illustrates a modiedform of clamping shackle which may b eemployed if desired'.

Similar charactersof reference refer to similar parts throughout theseveral views.

We shall rst refer to Figs. l to 6, inclusive.

An initially flat and resilient metal strap is conformed to provide apointer or cleaner varm 25, 50

a vhandle-eye 26, and a relatively short clamping arm 2'7.` The clampingarm 27 is arranged to lie at an acute angle to the adjacent portion ofthe pointer 25, even when the said clamping arm is released from theshackle vindicated at 28. Y

In some instances the tip of the pointer 25y is curved slightly awayfrom the plane of the rest of the pointer and is there given a permanentset, as indicated `at 29. The tip of the clamping arm is turned awayfrom the pointer, as indicated at 30, and is there given a permanent'set to serve as a stop for the clamping shackle 28.

` The clamping shackle 28 conveniently consists of a generallyrectangular metal stamping provided with a rectangular opening 3l.y Thelonger dimension of opening 31 is somewhat greater than the width of thestrap from which the pointer 25, handle-eye 26, and clamping arm 27 areformed.

The'shorter dimension of the opening 31 is such S0 that when theshackle'is embracing the pointer 25 and clamping arm 27, the uppermargin of said opening will'barely clear the tip of the clamping armoffset 30, providing there lis no abrasive strip carried bythe pointer,and provided further that 35 the clamping arm is pressed tightly againstthe adjacent portion of the pointer, as illustrated in Fig. 5,. There isno occasion for removing shackle clamp 28 from its embrace of thepointer 25 and clampingrarm 27 after the original assemblyof 90 the toolparts has been made. v

Indicated at 32 is a roll of a suitable flexible abrading strip. Theabrading strip may be formed of cloth, paper or other suitable flexiblematerial, and is preferably provided on but one of its faces with anysuitable abrasive such as sand, emery, carborundum, ground glass, or thelike. The abrading strip preferably has the same width as the metallstrap from which the pointer 25, handle-eye 26 and clamping arm 27 are100 formed, and is preferably coiled with its abrading face turnedinwardly. The abrading strip coil being coreless, it, uncoils itself asthe strip is progressed outwardly with the result that the outerconvolution of the coil exerts a radial force against ther inner wall ofthe eye 26 and thereby maintains a certain frictional engagement betweenthe outer convolution and the eye, which tends to hold the coil againstaxial displacement from the open faced eye. The strip is pulled out4embrace of the clamping 65 when the clamping arm 27 is in its releasedposition of Fig. 4, and for that position the coil will have uncoileditself sufficiently to exert a pressure against the inner wall of theeye. When the strip is clamped in place by sliding the ring 28 to theposition of Fig. 3, the eye is somewhat contracted after the manner ofa. band brake about the coil. This clamping action further holds thecoil against lateral displacement.

With the clamping shackle 28 moved to the non-wedging positionillustrated in Fig, 4, the roll 32 is placed in the handle-eye 26, andthe free end of the abrading strip is led from the roll between thepointer 25 andclainping arm 27, and is passed through the clampingshackle 28. The strip is then drawn 4over the upper surface of thepointer, around its tip, and thence along the lower surface of thepointer toward the handle-eye 28, being again passed through theclamping shackle 23, as illustrated in Figs. ll to 4.

The shackle clamp 28 is then moved from the position shown in Fig, 4. toor toward the position `shown in the preceding gures. When this movementof the shackle clamp occurs, the Lipper margin of the shacklecl'ampopening 31 cooperates with thev upper surface of the clamping arm 27 tomove the clamping arm toward the adjacent portion of the pointer 25securelyto clampthe abrasive strip where it passes between the point andthe upturned extremityl of the clampingY arm. At the same time, thelower margin of the shackley clamp aperture 3 1 `firmly engages thelower run ofthe .abrasive kstrip .and draws such strip tightlyover theupper and lower faces of the pointer, and clamps itin such tautcondition. .The tool isnow readyor use. Y

By grasping the handle-eye 26, the user .may

manipulate the abrasive carrying ,pointer to clean and/or smooth the.segments ofthe oommutator 33 1of.a. dynamo-electric machine which isvmore `or less diagrammatically illustrated at 34.v During thiscleaningand/ oiismoothing operation, the remainder "of theAdynamo-electric machine, including the commutator, is rotatedeithermanu- ,allyor under vpower, as preferred. The tool ,of

the'present invention similarly may be, utilized to -clean and/or smoothdistributor contacts, inter- .the p.ointer,. and the shackle. clampfisthen V,re-

turned to the wedging positionzindicatedin Figs. luto 3. The replaced orwornportion of the `abrasive .strip .is then removed, -conveniently bytearingit along and against the lower margin of the shackle clampopening 31.

M While we prefer Vto form .the .shackle clamp of stamped metal, asillustrated. inFigs, L to.,6

inclusive, this. shackle clamp may be formedfr'om asinglepiece I,ofstifwire having the conformation shownlin Fig. 7.

, Having thus illustrated and described f our 1invention in. apreferredembodiment thereof, what we claim as new .and desire to secureby Letters Patent of the United States, isp..

l, Ina tool of the. c lassdescribed a. ,metal straphaving 'gi'je'ater`width .than thickness, said strap being conformed to provide anelongated poi nter,.,az handle-eye and av clamping f arm, said clampingarm being angularly z disposed with relation to the pointer4 at ,a pointadjacent the handle end of the latter, a shackle clamp embracing saidpointer and clamping arm to hold upon the pointer a flexible abrasivestrip which has been extended from said handle-eye alongside and aroundthe tip of the pointer, the tip of said clamping arm being turned awayfrom the pointer to serve as a stop .for s aid shackle clampsubstantially as described.

2. An abrasive tool comprising a holder including a, supporting arm, anopen faced eye, a

'clamping arm overlying the supporting arm ad jacent the eye, theclamping arm being supported by the eye, and means for locking theclamping arm against the supporting arm, and a strip of abrasivematerial arranged as a coreless coil within the eye andexpanded againstthe inner surface of the eye, the strip extending outwardly fromtheVcoil and passing between the clamping arm and the supporting arm andalong and about the opposite end of the supporting arm.

3. An abrasive tool comprising a single length of resilient metal strapbent in a, plane perpendicular to its width to form a long 4 iivork-,ei'rigagirig arm, a short clamping arm overlying theinner endof theworking arm `a t a slight longitudinal inclination thereto and a Q-shaped portionforming an open faced eye, the ends o f theo-shapedportion continuing into the innerfends of -the respective arms, acorelessisupply rolll'offabrasive strip storedwithin the'eye tendingtoexp'and against, and thereby fri ctionallyY retaining the roll againstaxial .displacement within the eye, the outer convolution ofthe rollextending outwardly from the eye between the eye 'ari-ris and in,clampable relation therebetween -and continuingalong the one side of thelong arm; around ,the end thereof, and back along theotli'er sidethereof to va position beneathsthe shortar'in'and 'a ciampinsringembracing the t'w'p arms anja the superposed reaches of the strip 'and`working against theinclination of the s'hor't'armto'clainp thetwo'reaches ofthe'strip against'tlie long 4. An abrasive toollcori'prisiga holder 'including a supporting arm, an Aopen faced eye, a

Eriti clamping 'arnji overlying `the 'supporting Varm adjacent the eye,thewclanipirg arm 'being silp- 1ported by the eye, and Vnie'a'ri's yforAl'ocki'rfg'the clamping arm against 'the supportiiigfarmQanda strip ofabrasive material arranged'a'sa 'crele's's coil within lthe eye v'andexpanded "against -the inner surface of the eye, the 'strip extending"outwardly from the coilmand passing between 'the clamping arm and thesupp'ortih'garm andalon'g and about the opposite 'end of 'the'supporting arm, said clamping means 'being -applied 'to the clampingarm'betweenfthe region of contact of the clamping arm withthe abrasivestrip andthe connection between the Y('l'arnpiri'g 'ar-rn and the eye,whereby 'the "application vof said clamping 4means to operate theclamping'arin also slightly contracts the eye upon thecih..

v5. An "abrasive strip holder comprising; a. rneta1 .strap bent inaplane perpendicular to Eitswidth into ashape formingan .eyey the ends,of t he eye extending, in the samezdirection in Aspaced relation intoan integral supporting a r1`r1 .and Ac lampingarm respectively, the eyeadapted to receive a coilv of abrasive strip, the.outerf,cbnvo lution ofvwhich'extendsoutwardly'betwe'en the Vposed arms, and ano'fsetf in .theouter end of the Clamping arm turnedjaway 1-0m the;"sup DOIhg arm and ofsuch dimension "as'to'per'mit "iso embracing the superposed arms forclamping them together, the eye being adapted to receive a coil ofabrasive' strip, the outer convolution of which extends outwardlybetween the superposed arms in clampable relation thereto and along therespective sides of the supporting arm and. about the outer end.thereof, the clamping arm, when released by the shackle, beingsupported. and positioned in relation to the supporting arm solely bythe eye through the arcuate length thereof.

NORRIS F. MCNAUGHT. EDWARD H. PETERSON.

